The teams developing the OpenDocument Format (ODF) and Office Open XML (OOXML) standards should work together, evolving the two in parallel, the editor of the ODF standard has said in an open letter to the standards-setting community.

The Microsoft-sponsored OOXML document format is just days away from a critical meeting that will influence whether the International Organization for Standardization (ISO) will adopt it as a standard, as its rival ODF was adopted in May 2006. Relations between supporters of the two formats are, for the most part, combative rather than cordial.

Patrick Durusau, ISO project editor for ODF, or ISO/IEC 26300 as it is known there, thinks supporters of the two formats would be more productive if they allowed the formats to co-evolve, he wrote in his open letter. Durusau thoughtfully avoided the ODF and OOXML formats for his letter, choosing instead PDF, itself adopted as an ISO standard in December.

"If we had a co-evolutionary environment, one where the proponents of OpenXML and OpenDocument, their respective organisations, national bodies and others [sic] interested groups could meet to discuss the future of those proposals, the future revisions of both would likely be quite different," Durusau wrote.

"Peaceful co-evolution will mean better standards at lower costs in a more timely fashion," he said.

ODF, based on a file format used by Sun Microsystems' StarOffice application and the open-source productivity suite, won the support of OASIS, the Organization for the Advancement of Structured Information Standards, which fast-tracked it through the ISO standardisation process.

Microsoft offered its OOXML file format to ECMA International, which adopted it as one of its standards before proposing it to ISO for the same fast-track process.

An ISO committee rejected OOXML at a first vote last year. Since then, ECMA has been responding to the objections expressed in that vote, and the ISO committee will consider the revisions it proposed at a so-called ballot resolution meeting next week. There are 1,100 comments to process during the five days of the meeting. National standards bodies will then have one month to decide whether to change their vote in light of the changes made.

ISO accepts recommendations for fast-tracking from industry standards bodies. Specifications that take this route can become standards much more quickly and with less debate than by the regular route.

The two groups need a neutral forum where they can meet and learn from each other, Durusau suggested.

He expects his calls for co-operation to raise eyebrows, given that he is editor of the ODF standard at OASIS and project editor for it at ISO.

"Why am I advocating such co-operation? The answer is fairly simple. The difficulties we face today are the result of not talking to each other in the past and we can't change the past. But we can decide to act differently today," he said.

"Creating such an environment is going to take time and effort," Durusau said, offering a series of concrete steps the two groups can take, including talking to people working on the "other" standard, working toward a common meeting place and sponsoring conferences on multiple standards.

He suggested more companies should follow Novell's example: It participates in both the TC 45 committee working on Office Open XML and the ODF Technical Committee.